How does Apple's mobile phone block harassing calls and text messages?

Block contacts, filter unknown senders, and block strange numbers.

1. Block contacts: Go to Settings-Messages and Calls, select blocked contacts, and add contacts who do not want to receive messages and calls.

2. Filter unknown senders: in Settings-Info, turn on the function of "Filter unknown senders" and automatically put the information of non-contacts into a separate folder.

3. Block strange numbers: enter Settings-Telephone, select incoming call blocking and identification, turn on blocking all incoming calls, and manually add the numbers to be blocked.